The present invention relates to an eyeglass lens processing apparatus for processing an eyeglass lens.
An eyeglass lens processing apparatus is known in which an eyeglass lens chucked between lens chucks (lens rotary shafts) is processed by a roughing grindstone and a finishing grindstone disposed in a processing chamber. Such an apparatus includes grinding water supply means for supplying cooling grinding water to a contact portion between the grindstone and the lens so as to reduce a heat generated during a processing of the lens and to clean processing refuse attached to the lens. Additionally, since the processing refuse of the lens flies in the processing chamber due to a rotation of the grindstone or are accumulated in a drainage port provided at the bottom portion of the processing chamber during the processing of the lens (particularly, in case of a polycarbonate lens, etc. requiring a heat during the processing), some apparatuses include cleaning water supply means for flowing cleaning water to the downside of the processing chamber.
As a method of supplying a water to the inside of the processing chamber, there are known a water circulation type in which the water stored in a water tank is supplied by use of a pump and a water pipe direct connection type in which an electromagnetic valve is attached to a pipe extending from a water pipe and the water is directly supplied in terms of a water pressure of the water pipe.
Additionally, since drainage of the processing chamber contains the processing refuse, some apparatuses include a filter device such as a centrifugal separator for separating the water from the processing refuse. Such a filter device should be necessarily used in the water circulation type, and needs to be desirably used in the water pipe direct connection type.
In the known apparatus, since the cleaning water is supplied from the cleaning water supply means at a normal time during the processing of the lens irrespective of the material of the lens, a problem arises in that a water consumption amount is large. In order to improve the filtering (dewatering) efficiency by restricting a discharge of the dirty drainage upon using the filter device, it is desirable to reduce the water consumption amount during the processing.